Pneumatic tire with folded belt plies

ABSTRACT

A pneumatic vehicle tire with a folded belt having one or more layers of U-shaped cross section, in which with a positive camber of a vehicle wheel having the said tire mounted thereon, the free ends of the belt legs are located within the shoulder area of the tire and on that side of the tire which faces toward the vehicle on which the wheel is mounted and with a negative camber of the vehicle wheel are located within the shoulder area of that side of the tire which faces away from the vehicle.

ite States Patent [191 Rach et al.

[ Aug. 28, 1973 PNEUMATIC TIRE WITH FOLDED BELT PLlES [75] Inventors:Heinz-Dieter Rach, Garbsen;

Ekkehard Grolllch, l-lannover, both of Germany [73] Assignee:Continental Gummi-Werke Aktiengesellschalt, l-lannover, Germany [22]Filed: Apr. 26, 1971 [2]] Appl. No.: 137,423

[30] Foreign Application Priority Data FOREIGN PATENTS OR APPLICATIONS1,444,124 5/1966 France 152/354 Primary Examiner-Robert G. SheridanAssistant Examiner-George l-l. Libman Attorney-Walter Becker [57]ABSTRACT A pneumatic vehicle tire with a folded belt having one or morelayers of U-shaped cross section, in which with a positive camber of avehicle wheel having the said tire mounted thereon, the free ends of thebelt legs are located within the shoulder area of the tire and on thatside of the tire which faces toward the vehicle on which the wheel ismounted and with a negative camber of the vehicle wheel are locatedwithin the shoulder area of that side of the tire which faces away fromthe vehicle.

2 Claims, 5 Drawing Figures Reinforcing Layer PATENTEDAUGZB 191sReinforcing Layer INVENTORS HEINZ-DIETER RACH E/(K EHARD EROLZ ICHPNEUMATIC TIRE WITH FOLDED BELT PLIES The present invention relates to apneumatic vehicle tire with a folded belt having one or more layers ofU- shaped cross section. By folded belts" are understood annularreinforcing inserts which are pull-resistant in circumferentialdirection and which extend substantially over the width of the treadstrip, such reinforcing inserts which are arranged between the carcassand the tread strip comprising folded layers, for instance, rubberizedcord fabric layers, the folding edges of which extend in thelongitudinal direction of the tire.

With heretofore known pneumatic vehicle tires with folded belts ofU-shaped cross section, the layers forming the same are so arranged thatthey are provided in pairs with their free leg ends pointing outwardly.The free ends of the threads or the like forming the U- shaped layersthus form the lateral belt edges.

However, experience has shown that such belt constructions have thetendency to prematurely wear within the region of the tire belt. Forthis reason it has been suggested to surround the free thread ends atthe belt edge by additional fabric layers.

It is an object of the present invention to improve the endurancestrength of the above referred to pneumatic vehicle tires without takingsteps for enveloping the free thread ends.

This object and other objects and advantages of the invention willappear more clearly from the following specification in connection withthe accompanying drawing, in which:

FIG. 1 diagrammatically illustrates a radial section through a portionof a pneumatic vehicle tire according to the invention.

FIG. 2 shows the tire of FIG. 1 partially in section mounted on a rimhaving a positive camber.

FIGS. 3 to respectively illustrate cross sections of three modificationsof belts according to the invention for pneumatic vehicle tires.

The pneumatic vehicle tire with a folded belt according to the presentinvention is characterized primarily in that the free ends of the legsof the folded belt which extend substantially over the width of the beltare at a positive camber of the vehicle wheel arranged at that edge ofthe folded belt which faces the vehicle, and with a negative camber arearranged at that edge of .the folded belt which faces away from thevehicle.

The invention is based. on the employment of U- shaped layers whichextend substantially over the width of the belt or of the tread stripand thus determine the width of the belt. The edge of the U-shapedlayers which is formed by the folded or bent thread sections istherefore with a positive camber arranged on that side of the belt whichfaces away from the vehicle, whereas with a negative camber the saidedge is located on that side of the belt which faces the vehicle.

The invention is based on the finding that on one hand the belt withinthe range of its folding edge is liable to defects to a considerablyless degree than is the case with that edge of the belt which has thefree ending thread ends, and the invention is furthermore based on thefinding that it is expedient to take into consideration this differencein stress or wear as caused by the different types of suspensionscustomary in the motor vehicle industry. The folding edge of the belt isthus placed always at that edge of the tread surface which is subjectedto the highest stress, whereas the free ending thread ends should belocated at that side ofthe belt which is subjected to less stress inview of the camber of the vehicle wheel.

Referring now to the drawing in detail, the carcass I of a pneumatictire comprises pull-resistant threads, wires, or the like strengthmembers which extend at a right angle with regard to the circumferentialdirection of the tire. The ends of such strength members are anchored bybeing wound around the bead cores 2 in the tire beads 3. Between thecarcass l and the tread strip 4 with the tread surface 5 there islocated the belt 6 which extends substantially over the width of thetread surface 5 and forms a closed reinforcing insert which issubstantially pull-resistant in circumferential direction. Thisreinforcing insert comprises a rubberized cord fabric layer with the twosuperimposed legs 7, 8, and a folding edge 9 which extends in thecircumferential direction of the tire. The pull-resistant threads of thefolded belt 6 extend at an angle or incline with regard to thecircumferential direction of the tire. In view of the folding and due tothe inclined course of the cord threads, a cross connection or crossstructure is obtained. The pull-resistant threads in the leg 7 extend inone inclined direction whereas the pull-resistant threads in leg 8extend in the other inclined direction. The arrangement is such that, asshown in FIG. 1, the legs 7 and 8 extend over the entire width of thetread strip 6 so that the folding edge 9 is located within the region ofone tire shoulder and the free ends I0 of legs 7 and 8 are locatedwithin the region of the other tire shoulder. Thus, an asymmetric beltstructure is provided.

As will be evident from FIG. 2, it is important in this connection that,with the vehicle wheel arranged at a positive camber the arrow I1pointing toward the vehicle proper the folding edge 9 is located in theouter tire shoulder, in other words, at the edge of the belt 6 whichfaces away from the vehicle. The adjacent tire shoulder will duringoperation of the tire be subjected to a higher load. This load can beabsorbed by the folding edge at 9, whereas the arrangement of the freethread ends at 10 is sufficient in view of the fact that the pertainingtire shoulder is subjected to a lower specific load.

FIG. 1 shows a belt 6 composed of one layer. This arrangement, however,may according to FIG. 3 also be doubled by employing two superimposedU-shaped layers ll, 12.

According to FIG. 4, likewise two U-shaped folded rubberized cord fabriclayers 13, 14 are employed. These layers are, however, boxed into eachother in such a way that the folding edge 9 is located at one edge andthe folding edge I5 is located at the other edge of the belt.Furthermore, the arrangement is such that the free ends at 10 are allarranged on one side of the tire belt. The freely extending ends at 16have only a secondary meaning inasmuch as they are enclosed by the layer13.

It is also possible to combine a U-shaped folded belt layer with beltlayers extending in transverse direction. The folding edge 9 is,however, to be arranged in the manner shown in FIG. I, and the inserts17 extending in the transverse direction are located between the twolegs 19 and 18.

It is, of course, to be understood that the present invention is, by nomeans, limited to the specific showing in the drawing but also comprisesany modifications within the scope of the appended claims.

What we claim is:

l. A pneumatic vehicle tire especially of radially belted type withfolded belt means comprising at least one layer folded so as to define aU-shaped cross section with the legs thereof extending substantiallyover the entire width of said belt means providing a complete interfit,the arrangement being such that the free ends of said legs with apositive camber of the vehicle wheel are located within the shoulderarea and on that side of the tire which faces toward the vehicle andwith a negative camber of the vehicle wheel are located within theshoulder area of that side of the tire which ferential direction of thetire.

1. A pneumatic vehicle tire especially Of radially belted type withfolded belt means comprising at least one layer folded so as to define aU-shaped cross section with the legs thereof extending substantiallyover the entire width of said belt means providing a complete interfit,the arrangement being such that the free ends of said legs with apositive camber of the vehicle wheel are located within the shoulderarea and on that side of the tire which faces toward the vehicle andwith a negative camber of the vehicle wheel are located within theshoulder area of that side of the tire which faces away from thevehicle, said folded belt means including two folded U-shaped layers oneof which embraces the other one completely complementing the other, theinner one of said two folded U-shaped layers having its fold located onthat side of said belt means on which the free ends of the outer foldedU-shaped layer are located.
 2. An arrangement in combination accordingto claim 2, which includes at least one reinforcing layer interposedbetween the legs of at least one folded layer and extending in adirection transverse to the circumferential direction of the tire.